Preheat the oven to 375°F (190°C). Grease a 9x13-inch baking dish.

In a large skillet over medium heat, cook the ground beef until browned and fully cooked. Once cooked, transfer the beef to a bowl and set it aside.

Add the green peppers, red peppers, and onion in the same skillet. Sauté them until they become tender and slightly caramelized, about 5-7 minutes.

Add the cooked ground beef back into the skillet with the sautéed peppers and onions. Stir in the Worcestershire sauce, salt, and pepper. Cook for an additional 2-3 minutes to allow the flavors to meld together.

Cut the cream cheese into small cubes and add it to the skillet. Pour in the beef broth and stir everything together until the cream cheese has melted and formed a creamy sauce.

Remove the skillet from heat. Stir in the shredded mozzarella cheese until it melts and coats the beef mixture.

Transfer the beef mixture to the greased baking dish and spread it evenly. Lay the slices of provolone cheese on top.

Cover the baking dish with foil and bake in the preheated oven for 20 minutes. Then remove the foil and continue baking for another 10 minutes or until the cheese is melted and bubbly and the casserole is heated through.

Once the casserole is done, remove it from the oven and let it cool for a few minutes.

Garnish with fresh parsley and serve.